Combine like terms.

7 + 4x - 10x + 15

A. 22 - 14x

B. 22 - 6x

C. 22 + 6x

D. 11x - 5x

7 + 4x - 10x + 15 = 22 - 6x

You just need to sum terms of polynomial with the same stage of x and not to mix them out. Note that terms without x are actually terms with x^0 because x^0 = 1

Therefore we sum 7 and 15 = 22 and

we sum 4x and - 10x = - 6x

Answer is B)